File:Dragonfly metamorphosis.jpg|260px|thumb|A dragonfly in its radical final moult, metamorphosing from an aquatic nymph (biology)|nymph to a winged adult.
, '''moulting''' (British English), or '''molting''' (American English), also known as '''sloughing
''', '''shedding''', or in many invertebrates
''', is the manner in which an animal routinely casts off a part of its body (often, but not always, an outer layer or covering), either at specific times of the year, or at specific points in its life cycle.
Moulting can involve shedding the Epidermis (skin)|epidermis
), or other external layer. In some groups, other body parts may be shed, for example, wing
s in some insect
s or the entire exoskeleton